Grip device for elevators



(-No Model.) r

W. E. NIGKERSON.

GRIP DEVICE FOR ELEVATORS, &c. No. 397,382. Patented Feb. 5, 1889.

ra'rns lVIIiIiIAM E. NICKERSON, OF CAMBRIDGE, MASSACHUSETTS.

GRIP DEVICE FOR ELEVATORS, 3&0.

SPECIFICATION forming part of Letters Patent No. 397,382, dated February5, 1889.

Application filed October 22, 1888. Serial No. 288,803. (No model.)

To aZZ whom it 77mg concern:

Be it known that I, \VILLTAM E. Nickna- SON, of Cambridge, in the countyof Middle sex and State of Massachusetts, have invented a new and usefulImprovement in Grip Devices for Elevators, 850., of which the following,taken in connection with the accompanying drawings, is a specification.

lllyi'nvention relates to that class ol clutch or grip devices in whicha rotating f rictionpawl is used to prevent motion. in one directiononly, the object being to make a device that is sure and noiseless inits act-ion. This object I attain by the mechanism shown in theaccompanying drawings, in which- Figure 1 is a side elevation of mydevice as it appears in its application to the shaft of an elevatorwinding-arm. Fig. 2 is a longitudinal section taken through the centerof a winding-drum, myfriction device or grip bein applied to each end.

In the drawings I have shown one form or adaptation of myfriction-clutch. In this the central shaft, A, is stationary and haskeyed to it by two keys-one of which is shown at E, Fig. 1--a spool orbushing, B, divided in the center at V, Fig. 2,1'01 convenience inconnecting the pulley D to the shaft A. The two parts of the spool B Bare held to ether by the screw-bolts C O C C.

At each end of the spool B, I have cams B B, the peripheries of whichare either circular and eccentric with reference to the drum and shaft,or consist of compound curves that llow without abruptness into eachother, thus constituting contours having series of superior and inferiornodes, to and from which the rotating eccentric-pawls ll II traverse inthe act of gripping or freeing. The cams B B extend beyond the ends ofthe drum D, as shown in Fig. 2, and are made sufficiently thick to givea broad peripheral bearing for the eccentric-pawls H H. It is notnecessary to have distinct cams B 3 as bearing-surfaces, for

the eccentric-pawls H H could be formed directly on the spool 13,although this method would not be so good or easy to construct.

The eccentric-pawls II are mounted at each end of the main drum D uponaxial shafts K, to which they are attached by means of screws or bolts Nand washers or guard-disks M. Each of the eccentrics ll II is kept insuch a position by springs S S that itavill be ready to act whenneededthat is, when the d rum D moves in one direction relative to theshaft Athe tendency of the springs S S being to draw the eccentric-pawlsH in the direction indicated by the arrows Y Y, as shown in Fig. 1.. Thesprings S S are connected securely at 72 h to the eccentric-pawls H Hand at T T to the end face of the drum D. (See Fig. 1.) To prevent thefriction eccentric-pawls II II from turning too far backward and thuslocking the drum the way it should turn free, I place in each acheck-lug, L. (See Fig. I.)

My object in using cams B B for the cocentric-pawls II to operate upon,instead of circular disks turnin on their centers, is that in case thedisks are circular and on the centers then the eccentrie-pawls II, withthe exception of the comparatively-light action of the springs, havefriction alone to rotate them in a locking position, while if cams B areused, even if the eccentric-pawls H do not r0- tate at all, theperipheries would approach each other and thus lock.

The action of my device may be ex jilaincd as follows: In turning thedrum D in the direction indicated by the arrow W the eccentric-pawls IIwill move bodily in the direction indicated by the arrow but will eitherby the action of friction or by the springs S also rotate in the samedirection, thus causing a bearing and locking action between theeccentric-pawls and the cams B l-3-in fact, preventing the rotation ofthe drum D in the direction of the arrow \V.

In case the drum I) rotates in the direction opposite to that indicatedby the arrow IV, then the frictional bearings of the eccentricpawls H onthe cams B B have a tendency to make the eccentric-pawls rotate in theopposite direction to that indicated by the arrow IV and in a directionagainst the tendency of the springs S. I11 other words, thebearingsurfaces of the eccentric-pawls H and cams B will have a tendencyto separate, and thus leave the drum D free to rotate in a directionopposite to that indicated by the arrow W.

I claim- 1. In a grip device, the combination of the shaft A and bushingB, having cams B B,

with the eecentric-pawls H and drum D, all 111 testimony whereo't'Ihavesigned my name 10 operating together substantially as described, to thisspecification, in the presence of two suband for the purpose set forth.scribing witnesses, on this 20th day of Octo- 2. In a grip device, thecombination of the ber, A. D. 1888.

5 shaftA and bushing B, having cams B B, Y L 1 T 1 7 T With theeccentric -paw1s H, cheek-lugs L, ILL xK/IXERSOL' springs S, and drum D,all operating together Vitnesses: substantially as described, and forthe pur- FRANK G. PARKER, pose set forth. MATTHEW M. BLUNT.

